1. Animal Nutrition II (Ch. 41)

2. Keywords Roles of mouth, stomach, sm.&lg. Intestine in digestion Pepsin, pepsinogen Villi, microvilli Cecum Cellulose Cellulase

3. Stomach

4. Digestive mechanisms in stomach Mechanical Chemical enzymatic

5. Mechanical Mixing and churning

6. Chemical pH around 2 –Also breaks food down

7. Enzymatic Pepsin –Breaks down proteins

8. Why doesn’t pepsin digest stomach?

9. Activation of pepsin

10. Small intestine Most of the enzymatic digestion occurs here

11. Table 41.13 p. 803 in Campbell

12. Why doesn’t the small intestine digest itself? Fig. 37.13

14. Most nutrient absorption takes place in small intestine Structure: another example of increasing surface area

15. Structure of small intestine

16. Microvilli

17. Large intestine (colon) Major function is to reabsorb water

18. Here are a few review questions

19. What would happen if you had a defect in pepsin production?

20. A. carbohydrate would not be digested well B. meat would not be digested at all C. perhaps decreased absorption of protein

21. What would happen if you had a defect in salivary amylase production?

22. A. You would die B. You would be unable to digest starch C. The pH of the stomach would be affected D. None of the above What would happen if you had a defect in salivary amylase production?

23. Which of the following would you least like to donate to science while you are still alive? A. Cecum B. Pancreas C. Reproductive organs

24. What would happen if you had a defect in small intestine enteropeptidase?

25. Variations of vertebrate digestive system Herbivorous mammals –Specialized fermentation chambers

26. Coyote vs. Koala

27. Why does herbivory require specializations? Plant tissue –Harder to break up –Contains cellulose –Nutrients less concentrated than meat

28. Structure of cellulose

29. Only bacteria and protozoa can break down cellulose Via the enzyme cellulase

30. Cecum Pouch at junction between lg and sm intestine Large cecum in rabbits, some rodents, koala, horses Full of symbiotic bacteria

31. Symbiosis “living together”

32. Cecum function Fermentation chamber Bacteria breakdown cellulose Feces must be reingested